In sales, disagreement is inevitable. When you're negotiating with your prospect or objection handling, you'll have to prove your point to make the sale. But it's important to remember that there is a big difference between healthy, productive disagreements and heated arguments. In order for two parties to come to a mutually beneficial agreement, there has to be a level of professionalism and respect.

While navigating this territory can feel like a slippery slope, we've defined a few tips below to help you speak your mind without letting the situation spiral out of control.

So if you're raising your voice during a disagreement, will it negatively impact the delivery of your message? Or will it help you command attention?

MIT research fellow, Michael Schrage, suggests that your tone is often dependent on the situation, as well as the person you're disagreeing with.

"If you’re yelling because humiliating and demeaning people is part of who you are, you’ve got bigger professional issues than your decibel level," he explains. "But if raising your voice because you care is part of who you are as a person and communicator, your employees should have the courtesy and professionalism to respect that."

The lesson? Be in control of your own voice. If you feel yourself becoming agitated, take a moment to pause and think about the situation before choosing to raise your voice.

2) Don't use "you" statements.

Falling back on "you" statements when you're disagreeing with someone can easily be perceived as combative. Just look at the statements below to see what I mean.

"You always ask me to complete an last-minute assignment when you know that I already have my hands full," sounds more argumentative than "I'm feeling a little overwhelmed by the amount of work on my plate. Is there anyone else that can take that on?"

Notice the difference?

Let's look at a few more:

"You never fact-check your reports before sending them in." vs. "I noticed a few errors in your last report. Would it help if I showed you my approach for fact-checking?"

"You always forget to attach documents when you send an email." vs. "I had trouble locating the document you referenced in the email, mind sending it again?"

"You should pay more attention to what's being said in the meetings." vs. "I find it helpful to take notes during meetings to make sure I don't miss anything."

3) Avoid filler words or hesitant phrases.

Filler words like "um," "ah," and "uh" tend to signal doubt. These disruptions can instantly take away from the credibility of your claim, and also serve as a distraction for those listening.

Researchers John Sparks and Charles Areni set out to prove the influence of these hesitations by asking 118 undergraduate students to read a transcript of a testimonial about a scanner. One version of the testimonial used hesitations such as "I mean" and "um," and the other was fluid with no filler words. The results of the study revealed that when hesitant language was used, it was more difficult to convince them that the scanner was worth buying -- even when it was positioned as a better, lower priced scanner.

Point being, it's important to be aware of these placeholders -- and limit the use of them during disagreements. One way to work these fillers out of your speech? Try wearing an elastic band around your wrist and shifting the elastic to your other wrist any time you catch yourself using "um" or "uh."

4) Do your research.

To make a strong case, it's important that you do your research.

But don't just throw around numbers: "Tie data like this into the overall vision and goals of the business. A statistic in and of itself isn’t all that impressive. If you’re looking to resonate, provide context," explains John Bonini, Growth Director at Litmus.

This type of strategic preparation will make it difficult for others to poke holes in your assessment. It will also help to communicate that you're passionate about your resistance, and that you're not just disagreeing to disagree.

5) Don't get personal.

When a disagreement gets heated, it's easy for people to call upon "low blows." These personal attacks are often used as an intimidation tactic or defense mechanism, but that doesn't make them appropriate in business situations -- or any situation for that matter.

When disagreeing with someone, your claims should be based on the outcome over that you are debating, not on what the other person has done (or not done) in the past.

“Try to make sure the conversation stays focused on facts, not personalities,” encourages management professor Nate Bennett. And if the other person gets personal, remember that you are not your job.

"It's a lot easier to embrace criticism of your work when you don't let your work define who you are," insists Jeff Atwood, co-founder of Stack Exchange and Discourse. Even if someone says something out of line, avoid the itch to retaliate by keeping this notion in mind. Instead, refocus the discussion back to the subject matter at hand.

6) Be mindful of your body language.

When communicating disagreement, it's important to be aware of our non-verbal body language. You might be saying one thing, but if your gestures or facial expressions suggest another, it's easy to rub someone the wrong way.

If you want to disagree politely, try raising your eyebrows slightly to convey receptivity, or smile and nod along while others are speaking. This way, when it's your turn to talk, those around you will feel that you've actually listened to their take on things. (Want more body language tips? Check out this infographic on body language in business.)

7) Know your non-negotiables.

When you disagree with someone or something, there's no guarantee that it's going to be well received. In fact, often times, it probably won't be. But then what?

In an effort to disagree respectfully, you'll need to learn how to compromise. Aside from the obvious differences, business relationships are a lot like any other relationship we share with someone -- even a significant other.

That said, go into every negotiation knowing what you absolutely aren't willing to compromise on. While this approach may vary depending upon the exact situation, it will often make it easier for you to prioritize what matters and what you're willing to reconsider. At the end of the day, it's all about give and take.